Document Detail


Radon and thoron in cave dwellings (Yan'an, China).
MedLine Citation:
PMID:  10749527     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
222Rn and 220Rn concentrations were measured in cave dwellings and brick houses in the region of Yan'an (China) during summer 1997. The underground dwellings are built into Quaternary loess, and all investigated houses are founded on it. The median values of indoor 222Rn and 220Rn concentrations are 42 (n = 18) and 77 Bq m(-3) (n = 15) for brick houses and 92 (n = 23) and 215 (n = 17) Bq m(-3) for cave dwellings. To classify the dwellings in respect to their "cave-character," the fraction of walls having a direct contact to the loses is calculated for each dwelling. While the 222Rn concentrations are increasing with higher fractions, the 220Rn concentrations are not correlated with this fraction. On the other hand, due to the short half-life of 220Rn the distance from the measuring point to the walls is negatively correlated with the 220Rn concentration, while there is no correlation with the 222Rn concentration. Therefore, concentric isolines of 220Rn concentrations showing a strong gradient were detected in cave dwellings. An influence of the ventilation rate is distinct for 222Rn but weak for 220Rn. The effective dose rates for 222Rn and 220Rn and their progenies are calculated for brick houses (2.7 mSv y(-1)), cave dwellings (7.1 mSv y(-1)), and for traditional cave dwellings with a bed foundation built with loess (16.7 mSv y(-1)). These calculations are based on summer measurements only. It is expected that the true effective dose rates will be significantly higher.
Authors:
J Wiegand; S Feige; X Quingling; U Schreiber; K Wieditz; C Wittmann; L Xiarong
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Health physics     Volume:  78     ISSN:  0017-9078     ISO Abbreviation:  Health Phys     Publication Date:  2000 Apr 
Date Detail:
Created Date:  2000-05-24     Completed Date:  2000-05-24     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2985093R     Medline TA:  Health Phys     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  438-44     Citation Subset:  IM    
Affiliation:
University of Essen, Department 9-Geology, Germany. jens.wiegand@uni-essen.de
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MeSH Terms
Descriptor/Qualifier:
China
Housing*
Osmolar Concentration
Radiometry
Radon / analysis*
Radon Daughters / analysis
Soil Pollutants, Radioactive / analysis
Chemical
Reg. No./Substance:
0/Radon Daughters; 0/Soil Pollutants, Radioactive; 10043-92-2/Radon

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